1. Field of the Invention
This invention relates to stable bleach activator granules, specifically, granules which contain activators with the structure: ##STR2## wherein R is C.sub.1-20 branched or straight chain alkyl, alkoxylated alkyl, cycloalkyl, substituted aryl, alkenyl, aryl, alkylaryl; R' and R" are independently H, C.sub.1-4 alkyl, aryl; and L is a leaving group.
These activator granules are combined with either a peroxygen bleach base or a detergent base, which preferably includes a source of peroxide, and, optionally, surfactants, builders and other detergent adjuncts.
In a preferred embodiment, various granule additives are used to improve the solubility, durability, appearance and other important characteristics of the granules.
2. Brief Description of the Prior Art
Bleach activators have been widely described in the literature. For example, Boldingh et al., U.K. 1,147,871, describes bleaching and detergent compositions containing an inorganic persalt and acyloxyalkyl or acyl benzene sulfonates. It is claimed that such esters provide improved bleaching temperatures below 70.degree. C. when compared to compositions using the persalt alone.
These activators are represented by the formula: ##STR3##
wherein X=branched or straight chain alkyl or acyl radical containing 6-7 carbon atoms; R=H or alkyl radical having 1-7 carbon atoms; and M=an alkali metal, or ammonium radical.
Chung et al., U.S. Pat. No. 4,412,934, discloses bleaching compositions containing a peroxygen bleaching compound and a bleach activator of the general formula ##STR4##
wherein R is an alkyl group containing from about 5 to about 18 carbon atoms; L is a leaving group, the conjugate acid of which has a pK.sub.a in the range of about 6 to about 13. Chung et al. focuses on alkanoyloxy benzene sulfonates, which have been previously disclosed in G.B. 864,798, Hampson et al.
Thompson et al, U.S. Pat. No. 4,483,778, discloses bleach activators of the structure ##STR5## wherein R is C.sub.4-14 alkyl, R.sup.1 is H or C.sub.1-3 alkyl, X is --Cl, --OCH.sub.3, or --OCH.sub.2 CH.sub.3, and L is a leaVing group whose conjugate acid has a pK.sub.a of 4-30. The apparently crowded alpha carbon in the Thompson et al. compound may present hindered perhydrolytic reactivity.
Hardy et al., U.S. Pat. No. 4,681,952, discloses the use of a bleach activator compound of the formula [RX].sub.m AL, wherein R is hydrocarbyl, C.sub.6-20 alkyl substituted aryl, or alkoxylated hydrocarbyl; X is O, SO.sub.2, N(R.sup.1).sub.2, (R.sup.1)P.fwdarw.O or (R.sup.1)N.fwdarw.O, wherein for m=1, A includes ##STR6## oxybenzene sulfonate.
Burns et al., U.S. Pat. No. 4,634,551, discloses the use of amide esters of the formula ##STR7## wherein R.sup.1 and R.sup.2 are alkyl(ene) aryl(ene) or alkylaryl(ene) with 1-4 carbon atoms and R.sup.5 is H, an alkyl, aryl, or alkylaryl group with 1-10 carbon atoms.
Nakagawa et al., U.S. Pat. No. 3,960,743, disclose polymeric activators having the general structure ##STR8## in which R is purported to be C.sub.1-16 carbon atoms, a halo- or hydroxyl-substituted C.sub.1-16 alkyl or a substituted aryl group, B is hydrogen or a C.sub.1-3 alkyl group, M is hydrogen, C.sub.1-4 alkyl or alkali metal, wherein n is an integer of at least one when M is an alkyl group or n is an integer of least two when M is hydrogen or alkali metal. The polymeric activators of Nakagawa et al., however, suffer from a fatal defect. They do not disclose, teach or suggest perhydrolysis leavino orouos.
Schirmann et al., U.S. Pat. No. 4,221,675, substituted acyloxy N-acetamides of the structure ##STR9## The activators of the present invention do not contain a nitrogen heteroatom as does the activator of Schirmann et al. Moreover, in Schirmann et al., the group in question, an amide, does not bind to the acyl portion of the compound via an oxygen bond. Schirmann et al. do not teach or suggest what peracid is generated or where perhydrolysis occurs. Applicants have demonstrated that the alpha acyloxy, N-acetylacetamide compounds disclosed in Schirmann et al. provide minimal perhydrolysis at site of the amide bond, if at all, and thus do not effectively generate the desired peracid, peralkanoyloxyacetic acid. Thus, Schirmann et al. also do not have an effective leaving group.
Various references have taught how to formulate bleach activator granules using activators of the prior art. For example, Corey et al., U.S. Pat. No. 3,661,789, Green et al., U.S. Pat. No. 4,009,113, Wevers, U.S. Pat. No. 4,087,369, Saran, U.S. Pat. No. 4,372,868, Gray et al., U.S. Pat. No. 4,399,049, Gray, U.S. Pat. No. 4,444,674, Thompson et al., U.S. Pat. No. 4,483,778, Murphy et al., U.S. Pat. No. 4,486,327, Thompson et al., U.S. Pat. No. 4,539,130, Chung et al., E.P. 106,634, Parfomak, U.K. 2,178,075 and Divo, U.S. Pat. No. 4,681,695, all discuss ways of combining a peroxygen bleach activator with some binding or enrobing material.
Fong et al., U.S. Pat. No. 4,778,816 and U.S. Pat. No. 4,959,187, disclose and claim peracid precursors or bleach activators having the structure: ##STR10##
wherein R is C.sub.1-20 branched or straight chain alkyl, alkoxylated alkyl, cycloalkyl, alkenyl, aryl, substituted aryl, alkylaryl; R' and R" are independently H, C.sub.1-4 alkyl, aryl; and L is a leaving group.
It is further noted that the Fong et al. patents are the parents of application Ser. No. 07/258,225, which in turn is the parent of the present application. The entire text of Fong et al. is incorporated herein by reference. None of the art discloses, teaches or suggests that activators of the above structure can be incorporated in stabilized granules which contain, as a solubilizing aid, either magnesium sulfate, polyvinyl pyrrolidone, alkali aryl sulfonate, or a combination thereof.
Moveover, the art further does not disclose, teach or suggest the use of stiffeners, such as calcium silicate, magnesium silcate, or silica, in compositions of the type herein described.